<正> Objective: To compare and discuss the GOLD and the diagnostic criteria of severity of COPD adopt-ed by Chinase respiratory academy in 1997 and 2002. Method: The data of pulmonary function of 713 COPD from1991 to 2001 were reviewed by t-test. All patients were classified as mild, moderate and severe COPD by the diag-nostic criteria of Chinese respiratory academy in 1997 and traditional criteria of pulmonary dysfunction. Some associ-ated problems were discussed. Results: The data and results matched with the two criteria, but data of FEV_1/FVC inmild COPD group were different from the diagnostic criteria of GOLD and Chinese respiratory academy in 2002.